Effective connectivity of the multiplication network: A functional MRI and multivariate granger causality mapping study

• Published in: Human brain mapping 2011-09, Vol.32 (9), p.1419-1431
• Main Authors: Krueger, Frank, Landgraf, Steffen, Meer, Elke van der, Deshpande, Gopikrishna, Hu, Xiaoping
• Format: Article
• Language: English
• Subjects: Adenylate cyclase; Adult; Analysis of Variance; Biological and medical sciences; Brain - blood supply; Brain - physiology; Brain Mapping; calculation; Circuits; connectivity; Cortex (prefrontal); dorsolateral prefrontal cortex; Electrodiagnosis. Electric activity recording; Feedback; Female; Functional magnetic resonance imaging; Granger causality; Humans; Image Processing, Computer-Assisted; intraparietal sulcus; Investigative techniques, diagnostic techniques (general aspects); Kognitionspsychologie; Magnetic Resonance Imaging; Magnetresonanzverfahren; Male; mathematical competence; Mathematics; Mathematik; Medical sciences; Multiplikation; Nervous system; Netzwerk; Neural networks; Neural Pathways - blood supply; Neural Pathways - physiology; Neuroimaging; Neuronales Netz; Neuropsychologie; Oxygen - blood; precentral gyrus; presupplementary motor area; Principal Component Analysis; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Reaction Time; Time Factors; Young Adult
• ISSN: 0898-5898; 1065-9471; 1097-0193; 1873-1864; 1097-0193
• DOI: 10.1002/hbm.21119

Developmental neuropsychology and functional neuroimaging evidence indicates that simple and complex mental calculation is subserved by a fronto‐parietal network. However, the effective connectivity (connection direction and strength) among regions within the fronto‐parietal network is still unexplored. Combining event‐related fMRI and multivariate Granger Causality Mapping (GCM), we administered a multiplication verification task to healthy participants asking them to solve single and double‐digit multiplications. The goals of our study were first, to identify the effective connectivity of the multiplication network, and second, to compare the effective connectivity patterns between a low and a high arithmetical competence (AC) group. The manipulation of multiplication difficulty revealed a fronto‐parietal network encompassing bilateral intraparietal sulcus (IPS), left pre‐supplementary motor area (PreSMA), left precentral gyrus (PreCG), and right dorsolateral prefrontal cortex (DLPFC). The network was driven by an intraparietal IPS‐IPS circuit hosting a representation of numerical quantity intertwined with a fronto‐parietal DLPFC‐IPS circuit engaged in temporary storage and updating of arithmetic operations. Both circuits received additional inputs from the PreCG and PreSMA playing more of a supportive role in mental calculation. The high AC group compared to the low AC group displayed a greater activation in the right IPS and based its calculation more on a feedback driven intraparietal IPS‐IPS circuit, whereas the low competence group more on a feedback driven fronto‐parietal DLPFC‐IPS circuit. This study provides first evidence that multivariate GCM is a sensitive approach to investigate effective connectivity of mental processes involved in mental calculation and to compare group level performances for different populations. (Orig.).